I've got a 305 TBI Iroc-Z from '89.. And it recently crapped out on me. :-/

Time is somewhat limited, as is funds, so I can't just do a swap to a 350 or anything like that... I need a good replacement for the stock unit that will keep drivability and mileage good. I'm not really looking for insane amounts of power, but if that could be had with great mileage...

Any suggestions? I was looking through SUmmit and saw the TBI unit meant for the 350, but I have a 305, so I'm pretty sure there'd be some mixture issues there. Any websites & suggestions are appreciated.

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89 iroc-z 305 tbi
k&n filtercharger, open element air filter. nuffin' else

 

Why not rebuild the unit and send the injectors off to be refurbished? Total cost probably less than $100. A monkey with two broken thumbs could rebuild a TBI.

Unless it "crapped out" in some massive way I didn't pick up on in your post.

 

Well, the regulator housing is bent inward.. I have no idea how that happened.. so it doesn't quite seat right (the spring sorta pushes it off to the side). Also, I did recently get a rebuilt kit. Inside the regulator is a type of gasket with that metal ring in the middle. The spring rests on one end, and on the other end it's supposed to fit into a little pit. The stock piece was raised up more than the replacement is, so basically my regulator isn't regulating anything anymore and dumping way too much gas into the engine. I suppose I could simply go to the junkyard to pick this piece up, but I would like to be able to get a better unit if possible.

 

So just the regulator is mesed up? You won't get a better tbi unit for a 305. If it's just the regulator get an adjustable one out of www.jegs.com or something.

 

or...

take your diaphram, the rubber peice with the metal disc on it, and put it on your injector pod like its supposed to be. now, measure the depth of the regulator cup. replace the spring with something hard, that fits in the cup that wont let the diaphram move much at all. put it back together.

NOW, put an external adjustable fuel pressure regulator and maybe a guage on your return fuel line.

problem solved, better than stock.

or....

replace it with the vacuum adjustable regulator. info can be found here.
https://www.thirdgen.org/messgboard/...ML/001842.html
ALSO BETTER THAN YOUR STOCK CONFIG THATS FUBAR.

btw, did you drop it or something?

edit:

or... you could read up on how to make the one your have adjustable. go to tech section from the homepage here. people here can help with that also.

[This message has been edited by snflupigus (edited August 03, 2001).]

 

The regulator's already been made adjustable.. Drilled out the weld and cut a groove in the threaded rod. But that was done a while ago. It was after a rebuild that it happened..

I don't know exactly what happened, I must have dropped it. The regulator cup is dented in and at an angle, so the spring can't seat straight up and down. I can't adjust fuel pressure either way. Screw all the way in and all the way out doesn't make a difference. I like the idea of the link you sent me.. Does that bolt on in place of the stock regulator, or does it go somewhere else before it? I guess it wouldn't matter.. Since the stock regulator is letting wayy too much flow through, an aftermarket one anywhere couldn't hurt. (As opposed to if it was letting too LITTLE fuel through.)